The present invention relates to a scribing device or scriber for forming (scribing) a scribe line on a work formed of a brittle material such as glass, semiconductor or like.
There is known a scribing device for forming a scribe line on a surface of a work or work piece. In this working, when a cutter which is now vibrating is pressed against the work surface, vertical crack will be generated on the work surface so as to extend in thickness direction thereof and, in this state, when the cutter is moved on the work surface, a continuous scribe line (cracks) will be caused on the work surface. After the formation of such scribe (scribed) line, by bending the work along the scribe line, the work is broken.
FIG. 7 shows a scribing device having a conventional structure and provided with a scribing body 2 for vibrating a cutter 1. The scribing body 2 has a housing in which a piezoelectric element as vibration generation member is accomodated. A shaft 4 is disposed so as to extend downward, as viewed, from a lower portion of the housing and adopted to be vertically guided by a guide member disposed inside the housing 3. The cutter 1 mentioned above is mounted to the lower end portion of the shaft 4. As such cutter 1, there may be utilized a square-pyramid shaped diamond tool. When the piezoelectric element is vibrated, the shaft 4 is then vibrated together with the cutter 1.
The housing 3 is attached to a slide block 5, which is mounted to a table 6 through a guide member 7 such as linear guide. The guide member 7 operates to guide the slide block 5, the housing 3 and the scribing body 2 with the shaft 4 and the cutter 1 in a linearly movable manner with respect to the table 6. The table 6 is moved by a moving, i.e. driving, mechanism 10 with respect to a work (work piece) 9.
A pair of magnets 8a and 8b mounted to the sides of the scribing body 2 and the table 6 repulse from each other so as to adjust stationary load applied by the cutter 1 to the work 9. When the cutter 1 is raised by the repulsive force of the magnets 8a and 8b, static load (that is, a load which is applied from the cutter to the work at the time of no vibration of the vibration generating member) can be adjusted. In this time, the vertical motion (rising or floating motion) of the scribing body 2 is guided by the guide member 7.
According to the scribe device of the structure mentioned above, the cutter 1 can be vibrated, and the static load applied to the work 9 from the cutter 1 can be suitably adjusted in accordance with kinds, types or thickness of the work to be broken.
In the conventional scribing device of the characters and structures mentioned above, however, the guide member 7 for guiding the rising motion of the scribing body 2 and the guide member for guiding the vibration of the shaft 4 are disposed independently at the positions apart from each other by distance L in FIG. 7 in the lateral direction. Therefore, when the shaft 4 is vibrated, a moment load is generated to the guide member 7 which cantilevers the scribing body 2.
If such moment load is generated, the cutter 1 is vibrated in the horizontal direction, as well as in the vertical direction as viewed in FIG. 7. When the cutter 1 is horizontally vibrated, a horizontal component force will be generated to the load applied to the work 9 from the cutter 1, and according to such component force, horizontal crack may be generated to the surface of the work 9, thus deteriorating the work 9, and hence, being inconvenient.
In addition, when the vibration generating member is vibrated, the scribing body 2 as well as the cutter 1 is vibrated. However, the follow-up performance of the guide member 7 will be made worse due to the moment load applied to the guide member 7, and accordingly, resistance will be caused at the time of the vibration of the scribing body 2.
Furthermore, the separate, i.e. independent, location of the guide member 7 for guiding the rising motion and the guide member for the vibration makes complicated the structure of the scribing body and increases its weight. In a case where the work 9 has a worse degree of flatness or where the cutter is moved so as to intersect the once scribed line, the scribing body 2 is vertically raised up and down, so that when the entire weight of the scribing body is increased, the inertia force of the scribing body is also increased, thus causing large variation of the load applied to the work 9 from the cutter 1.
An object of the present invention is therefore to substantially eliminate defects or inconveniences encountered in the prior art described above and to provide a scribing device capable of substantially suppressing horizontal vibration of a cutter in the scribing device and vibrating the cutter only in the vertical direction with simple structure of a vibrating portion having reduced weight.
This and other objects can be achieved according to the present invention by providing, in one aspect, a scribing device for forming a scribe line on a work comprising:
a vibration generator for generating vibration;
a cutter for cutting a work by utilizing vibration of the vibration generator;
a shaft extending vertically downward from the vibration generator so as to transmit the vibration of the vibration generator to the cutter;
a guide unit for guiding a linear motion of the shaft to the cutter in a central axis direction thereof; and
a load adjusting mechanism for adjusting a load to be applied to the work from the cutter, the load adjusting mechanism being operated by means of magnetic force,
wherein the guide unit guides a moving motion of the shaft by the load adjusting mechanism and guides the vibration of the shaft caused by the vibration generated by the vibration generator.
According to this aspect of the present invention, the guide unit attains commonly the function of guiding the vibration of the shaft caused by the operation of the vibration generator and the function of guiding the upward moving (rising or floating) motion of the shaft by means of load adjusting mechanism. Accordingly, since it is not necessary to independently (separately) disposed two guide members for achieving the above two functions, respectively, as made in the prior art, any moment load is not caused. Thus, the horizontal vibration of the cutter can be prevented from causing and the cutter can be vibrated smoothly only in the vertical direction.
In addition, since the single guide unit acts to attain both the guiding functions mentioned above, the structure of the guide unit can be made simple and light in weight, thus making small the variation of the load applied to the cutter.
For such guide unit, there may be preferably utilized, for example, a linear guide, a ball spline guide, a ball bush guide or a slide bearing guide.
In this aspect, the following preferred examples may be adopted.
The scribing device may further comprises a cutter moving mechanism for moving the cutter along the work.
The shaft is formed, at an outer peripheral surface thereof, with a rolling member rolling portion, the guide unit comprises an outer sleeve fitted to the shaft, the sleeve being formed, on an inner peripheral surface thereof, with a rolling member rolling portion, and a number of rolling members interposed between the rolling member rolling portion formed on the shaft and the rolling member rolling portion formed on the outer sleeve. The rolling members may be balls and the rolling member rolling portion formed on the shaft and the rolling member rolling portion formed on the outer sleeve may be grooves.
The vibration generator has a center line and the shaft has a center line which substantially accords with the center line of the vibration generator.
The vibration generator is accommodated in a housing and a coned disc spring is disposed in the housing at a portion between the shaft and the vibration generator so as to follow up the vibration of the shaft with that of the vibration generator.
A table may be further provided for the scribing device, which is movable with respect to the work, the guide unit is mounted to the table which is moved by the moving mechanism.
The load adjusting mechanism may comprise a pair of magnets disposed apart from each other in the shaft vibrating direction, a piezoelectric element, or a super-magnetostrictive element.
According to these preferred examples, a scribe line can be well described by moving the cutter along and on the surface of the work.
Since the shaft is fitted into the outer sleeve so as to surround the outer periphery of the shaft, the shaft can be smoothly and stably guided in a vertical direction when the shaft is vibrated. Moreover, since the rolling members are interposed between the shaft and the outer sleeve, resistance, which is caused at a time of the vibration of the shaft, is possibly reduced.
In addition, the vibration of the vibration generator can be transferred to the shaft with high efficiency in the central axis direction thereof without imparting adverse moment load to the shaft.
The location of the coned disc spring will make easy to transfer only the vertical (axial) vibration.
In a further aspect of the present invention, there is also provided a scribing device for forming a scribe line on a work comprising:
a table disposed to be movable with respect to the work;
a moving mechanism for moving the table;
a vibration generator for generating vibration;
a cutter for cutting the work by utilizing vibration of the vibration generator;
a shaft extending vertically downward from the vibration generator so as to transmit the vibration of the vibration generator to the cutter;
a guide unit, mounted to the table, for guiding a linear motion of the shaft in a central axis direction thereof; and
a load adjusting mechanism for adjusting a load to be applied to the work from the cutter, the load adjusting mechanism comprising a magnet. The magnet includes a pair of magnet pieces disposed apart from each other in the shaft vibrating direction.
According to this aspect, substantially the same advantageous effects and functions as those mentioned with reference to the first aspect will be achieved.
The nature and further characteristic features of the present invention will be made more clear from the following description with reference to the accompanying drawings.